The present invention relates to N-acrylimino compound of formula (I): wherein X is O or S, in particular O Het is a 5- or 6-membered carbon-bound or nitrogen-bound heterocyclic ring, W1-W2-W3-W4 represents a carbon chain group connected to N and C═N, and thus forming a saturated, unsaturated, or partially unsaturated 5 or 6 membered nitrogen containing heterocycle, wherein W1, W2, W3 and W4 each individually represent CRvRw, R1, R2 may be hydrogen, halogen, etc. R3 is selected from the group consisting of hydrogen, halogen, CN, C1-C6-alkyl, etc. R4 is selected from the group consisting of hydrogen, halogen, CN, C1-C10-alkyl, etc. R5 is selected from the group consisting of hydrogen CN, C1-C10-alkyl, C2-C10-alkenyl C3-C8-cycloalkyl, S(O)nNR9aR9b, O—NR9aR9b, NR9aR9b, NR9a NR9aR9b, NR9aC(═O)R7a, NR9aC(═S)R7a, NR9aC(═O)NR9aR9b, NR9aC(═S)NR9aR9b, C(═O)OR8, C(═O)NR9aR9b, C(═S)NR9aR9b, C(═O)R7a, C(═S)R7a, a moitey Q-phenyl, where the phenyl ring is optionally substituted with 1, 2, 3, 4 or 5 identical or different substituents R10, and a moiety Q-Het# where Het# represents a 3- to 10-membered saturated, partly saturated or unsaturated aromatic heterocyclic ring. The invention also relates to the use of the N-acrylimino heterocyclic compounds, their stereoisomers, their tautomers and their salts, for combating invertebrate pests. Furthermore the invention relates also to methods of combating invertebrate pests, which comprises applying such compounds.
